A phase-locked loop circuit is known as a circuit for generating a signal that is synchronized with a reference clock.
A phase-locked loop circuit, for example, compares a phase frequency of an input signal with a phase frequency of an output signal, and generates a voltage of a magnitude corresponding to a difference between the phase frequencies. The phase-locked loop circuit generates, as an output signal, a signal having a frequency corresponding to a magnitude of the generated voltage. The output signal is fed back to be compared with the input signal, and a frequency of the output signal is controlled in accordance with a frequency of the input signal.